Question

What is the sixth term of a number pattern that begins with 185 and subtracts 15?

A. 170
B. 110
C. 125
D. 95

Answer 1

Answer: (B) 110

Explanation:

The formula for an arithmetic sequence is:

`a_n = a_1 + d(n - 1)\qquad \text{where}\ a_1\ \text{is the first term, d is the difference, n is the term}`

It is given that a₁ = 185, d = -15, and n = 6

a₆ = 185 - 15(6 - 1)

= 185 - 15(5)

= 185 - 75

= 110

Check:

n = 1: 185

n = 2: 185 - 15 = 170

n = 3: 170 - 15 = 155

n = 4: 155 - 15 = 140

n = 5: 140 - 15 = 125

n = 6: 125 - 15 = 110
`\checkmark`

Answer 2

110 is answer.

Explanation:

Given that first term is 185

Each term is got by subtracting 15 from the previous term

Hence we have an arithmetic sequence with a = 185 and d = common difference =-15

6th term would be

a_6 = a+(6-1)d = 185+5(-15)

=110

Verify:

185, 170, 155,140,125,110

We get by subtracting 15 the same answer as the 6th term